Hispanic women are the fastest growing minority group in the US and are more likely to begin their pregnancies overweight or obese as compared to non-Hispanic white women. The overall goal of this randomized controlled trial is to test the efficacy of a culturally and linguistically modified, individually- tailored lifestyle intervention to reduce excess gestational weight gain (GWG), increase postpartum weight loss, and improve maternal metabolic status among overweight/obese Hispanic women. Specific aims are to evaluate the impact of the intervention on 1) GWG and postpartum weight loss, 2) pregnancy and postpartum biomarkers of insulin resistance (i.e., glucose, insulin, HbA1c, HOMA, leptin, adiponectin), 3) postpartum biomarkers of cardiovascular risk (i.e., blood lipids, blood pressure), 4) offspring outcomes (i.e., anthropometric measures and biomarkers of insulin resistance), and 5) to evaluate the cost-effectiveness of the intervention per average incremental improvement in the outcome variables. Overweight/obese Hispanic women will be recruited in early pregnancy (10 weeks gestation) and randomly assigned to a Lifestyle Intervention (n=150) or a Comparison Health and Wellness (control) Intervention (n=150). The intervention will utilize exercise (R01NR011295) and dietary intervention materials (R18DK067549) culturally adapted for Hispanics and shown to be efficacious in our previous controlled trials in this ethnic group. Multimodal contacts (i.e., in-person, telephone counseling, and mailed print-based materials) will be used to deliver the intervention during pregnancy (12 wks gestation to delivery) continuing into postpartum (6 wks to 6 mos postpartum); follow-up will continue to 1 yr postpartum. Targets of the intervention are to achieve Institute of Medicine Guidelines for GWG and postpartum weight loss; ACOG guidelines for physical activity through increasing walking and developing a more active lifestyle; and reduction in total calories by following a balanced healthy diet in compliance with American Diabetes Association guidelines. The intervention draws from Social Cognitive Theory and the Transtheoretical Model and includes strategies for partner and/or family support to address the specific social, cultural, and economic challenges faced by underserved Hispanic women. Measures of compliance will include actigraphs and Hispanic food frequency questionnaires. The proposed project builds upon the expertise of the investigative team in conducting randomized controlled trials of exercise interventions among Hispanic pregnant women (R01 DK074876) and dietary interventions among low-income Hispanics with type 2 diabetes (R18 DK0658850) and can readily be translated into clinical practice in underserved and minority populations.